protected virtual int?GetSmartIndentation(ITextSnapshotLine line)
{
ITextSnapshot snapshot = line.Snapshot;
SnapshotPoint contextEndPosition = line.Start;
SnapshotPoint endPosition = line.EndIncludingLineBreak;
SnapshotPoint endPositionOnLine = line.End;
IReferenceAnchors anchors = FindNearestAnchors(contextEndPosition);
IAnchor previous = anchors.Previous;
int spanEnd = Math.Min(line.Snapshot.Length, endPosition.Position + 1);
Span span;
IAnchor enclosing = anchors.Enclosing;
if (enclosing != null)
{
span = Span.FromBounds(enclosing.TrackingSpan.GetStartPoint(snapshot).Position, spanEnd);
}
else if (previous != null)
{
// at least for now, include the previous span due to the way error handling places bounds on an anchor
span = Span.FromBounds(previous.TrackingSpan.GetStartPoint(snapshot).Position, spanEnd);
}
else
{
span = Span.FromBounds(0, spanEnd);
}
var diagnosticsPane = DiagnosticsPane;
if (diagnosticsPane != null)
{
diagnosticsPane.WriteLine(string.Format("Smart indent from anchor span: {0}", span));
}
ITokenSource bufferTokenSource = GetTokenSource(new SnapshotSpan(snapshot, span));
ITokenSource tokenSource = new CodeCompletionTokenSource(bufferTokenSource, endPosition);
ITokenStream tokenStream = new CommonTokenStream(tokenSource);
IDictionary <RuleContext, CaretReachedException> parseTrees = GetParseTrees(tokenStream, anchors);
if (parseTrees == null)
{
return(null);
}
var indentLevels = new SortedDictionary <int, IList <KeyValuePair <RuleContext, CaretReachedException> > >();
foreach (var parseTree in parseTrees)
{
if (parseTree.Value == null)
{
continue;
}
IParseTree firstNodeOnLine = FindFirstNodeAfterOffset(parseTree.Key, line.Start.Position);
if (firstNodeOnLine == null)
{
firstNodeOnLine = parseTree.Value.FinalContext;
}
if (firstNodeOnLine == null)
{
continue;
}
int?indentationLevel = GetIndent(parseTree, firstNodeOnLine, line.Start);
if (indentationLevel == null)
{
continue;
}
IList <KeyValuePair <RuleContext, CaretReachedException> > indentList;
if (!indentLevels.TryGetValue(indentationLevel.Value, out indentList))
{
indentList = new List <KeyValuePair <RuleContext, CaretReachedException> >();
indentLevels[indentationLevel.Value] = indentList;
}
indentList.Add(parseTree);
}
if (indentLevels.Count == 0)
{
return(null);
}
int indentLevel = indentLevels.First().Key;
if (indentLevels.Count > 1)
{
// TODO: resolve multiple possibilities
}
return(indentLevel);
}
protected abstract IDictionary<RuleContext, CaretReachedException> GetParseTrees(ITokenStream tokens, IReferenceAnchors referenceAnchors);
protected abstract IDictionary <RuleContext, CaretReachedException> GetParseTrees(ITokenStream tokens, IReferenceAnchors referenceAnchors);
protected override IDictionary <RuleContext, CaretReachedException> GetParseTrees(ITokenStream tokens, IReferenceAnchors referenceAnchors)
{
Antlr4CodeCompletionParser parser = new Antlr4CodeCompletionParser(tokens);
parser.RemoveErrorListeners();
parser.BuildParseTree = true;
parser.ErrorHandler = new CodeCompletionErrorStrategy();
Antlr4ForestParser forestParser;
if (referenceAnchors.Previous != null)
{
switch (referenceAnchors.Previous.RuleIndex)
{
case GrammarParser.RULE_ruleSpec:
forestParser = Antlr4ForestParser.Rules;
break;
default:
forestParser = null;
break;
}
}
else
{
forestParser = Antlr4ForestParser.GrammarSpec;
}
if (forestParser == null)
{
return(null);
}
var originalInterpreter = parser.Interpreter;
try
{
IntervalSet wordlikeTokenTypes = IntervalSet.Of(0, GrammarParser._ATN.maxTokenType);
parser.Interpreter = new FixedCompletionParserATNSimulator(parser, GrammarParser._ATN, wordlikeTokenTypes);
return(forestParser.GetParseTrees(parser));
}
finally
{
parser.Interpreter = originalInterpreter;
}
}
